Some times when you run Oracle Reports 6i from network shared folder or from the folder you just copy and paste the Oracle forms & reports builder instead of a proper installation then you get the error REP-0118 Unable to create temporary file.
This is due to missing registry setting for variable REPORTS60_TMP, to resolve this you should have to write registry values as described below:
Run the windows registry editor by typing regedit in start menu run command.
After that navigate to HKEY_LOCAL_MACHINESOFTWAREORACLE
If ORACLE does not exists in HKEY_LOCAL_MACHINESOFTWARE then create a new key ORACLE.
After that create a new string value by right clicking on ORACLE key as shown below:
And set the value of your any temporary file folder as shown below:
After setting the property it should display as shown below:
Now run your Reports builder and it will not show the same error.